The magnetic susceptibility, grain size, paleomagnetic data, and element contents from the BKZK07 borehole, Northeast China

The BKZK07 core (47°25′42″ N, 125°55′00″E) is located in the northern part of the Songnen Plain, and is close to 100% coring rate. Lithologies of the 51-m long core were first described and logged following standard procedures in core logging . We take 148 oriented samples along the core (ca. 1 sample every 35 cm) for magnetostratigraphic dating, and selected 642 samples with about 8 cm resolution for grain size analysis. A total of 1,252 samples were ground into powder and passed through 200-mesh sieve, measured by a portable energy-dispersive Innov-X Systems X-ray fluorescence spectrometer in geochemistry mode using beam 1 (50 kv) and beam 2 (10 kv) to acquire the abundance of XRF element contents at the China University of Geosciences (Wuhan). A total of 512 powdered samples were subsequently packed into non-magnetic cubic containers (2 cm × 2 cm ×2 cm) for low- (χ_lf) and high-(χ_hf) frequency magnetic susceptibility measurements using an AGICO MFK1-FA Magnetic Susceptibility System housed in the Chinese University of Geoscience (Wuhan). χ_lf and χ_hf were measured at 976 Hz and 15616 Hz, respectively.

BKZK07钻孔岩芯（47°25′42″N，125°55′00″E）位于松嫩平原北部，取芯率接近100%。研究人员按照岩芯编录标准流程，首次对这套总长51米的岩芯开展了岩性描述与测井工作。沿岩芯共采集148块定向样品（约每35厘米采集1件）用于磁地层定年；另选取642件分辨率约8厘米的样品开展粒度分析。总计1252件样品被研磨成粉末并过200目筛，随后在中国地质大学（武汉）采用便携式能量色散型Innov-X Systems X射线荧光光谱仪（X-ray fluorescence spectrometer），以地球化学模式分别使用光束1（50kV）和光束2（10kV）进行测试，获取XRF元素含量丰度数据。此后，将512件粉末样品装入非磁性立方容器（2cm×2cm×2cm），在中国地质大学（武汉）的AGICO MFK1-FA型磁化率仪中开展低频（χ_lf）与高频（χ_hf）磁化率测量，其中低频磁化率的测量频率为976Hz，高频为15616Hz。